Alsace-Lorraine

A region in between France and Germany, currently belonging to France. Very much sought-after real estate, baby. Prime. Extremely fertile. Resources, dig? You shoulda seen prices around 1914 or so. SKY HIGH. Until the Germans invaded, that is.

Here's the deal. Franco-Prussian War - Prussia, the largest state in what will soon be Germany, hands a good old fashioned whuppin' to France, and in addition to forcin' them Frenchies to pay up in cold hard cash, siezes lovely little A-L. This doesn't sit too well with France, and it provides good material for lots of agitation in F-Land.

Enter WWI. Lots o guys die. Rat a tat tat. Outcome: France wins, with a little help from basically half of Europe. The 1919 Treaty of Versailles gives France back its little precious, and all is right with the world... Until, of course, a little number I like to call World War II.